Production of absorbent articles such as baby diapers, adult incontinence diapers and belted diapers is performed at high speed. Due to the relatively low basis weight of materials used in the construction of such products, measures have to be taken to prevent the materials from lifting and/or fluttering during their passage through air. For continuous webs, such as the backsheet and topsheet materials, lifting and fluttering can be controlled by maintaining the webs under tension. However, many contemporary absorbent articles comprise side panels in addition to the topsheet and backsheet materials. Such side panels are used to provide the absorbent article with a transverse extension sufficient to allow the article to be fastened around the waist of a user. Although, during production, a continuous web of side panel material could be united with the continuous webs of backsheet and topsheet materials and thereby kept under tension, the side panel material in the crotch region has to be removed to create the finished product. Since the side panel material is often advantageously an elastic material, such a production technique, whilst addressing the problems of lifting and fluttering, results in uneconomic utilisation of material.
In order for absorbent articles to be secured around the waist of a wearer, it is necessary to provide the article with a fastening system. Contemporary fastening systems utilise a fastening tab secured to rear side panels. Particularly for articles having elasticised side panels, measures have to be taken to ensure that the fastening tabs are adequately affixed to the side panels. Such measures include deadening the elastic properties of the elasticised material in the region at which the fastening tape is to be secured to the side panel. Furthermore, since the fastening tab is normally directly attached to the side panel, compatibility of the materials is required.
A process for assembling elasticised side panels, or “ear portions”, is described in WP-A-96/03952. According to its abstract, the process involves attaching at least one first fastener to a first web of side panel material and at least one second fastener to a second web of side panel material. A web of bridge material is provided with first and second side edge regions. The first web of side panel material is attached to the first side edge region of the web of bridge material, and the second web of side panel material is attached to the second side edge of the web of bridge material. The second web of side panel material is arranged to provide a cross-directional alignment between at least one corresponding, laterally opposed pair of the first and second fasteners. The web of bridge material and the first and second webs of side panel material are divided to provide at least one composite bridge assembly having a bridge member interconnecting a laterally opposed pair of first and second side panel members. The composite bridge assembly is secured to an appointed article web with the first and second side panels of the laterally opposed pair of side panel members located at opposite side regions of the article web.
In spite of the various known ways for integrating side panels and fasteners in absorbent articles, there remains a need for a method of producing an absorbent article in which the utilisation of side panel material is optimised at the same time that attachment of fastening tabs is facilitated.